1. Technical Field
The present invention relates to a method for manufacturing a liquid jet head.
2. Related Art
A known example of a liquid jet head for ejecting liquid from nozzle openings includes a flow path forming substrate formed with pressure generating chambers at least communicated with nozzle openings, piezoelectric elements formed on one surface side of the flow path forming substrate, and a reservoir forming plate having a part of a reservoir, in which the reservoir is formed via a penetrated portion penetrating a vibration plate and a lamination film provided on the vibration plate. For example, JP-A-2006-088665 discloses a technique in which the reservoir is formed by penetrating the reservoir by wet etching so that processing waste during the penetration is not produced.
In JP-A-2006-088665, the reservoir forming plate having formed therein a part of the reservoir is bonded to the flow path forming substrate in which a wiring layer is formed in a region thereof where the penetrated portion is formed, and a surface of the flow path forming substrate opposite to the wiring layer is wet-etched until the wiring layer is exposed, thereby forming a flow path. Next, a protective layer is formed on at least the pressure generating chambers and the flow path which is to be penetrated. Then, a release layer whose adhesion to the wiring layer is greater than the adhesion between the wiring layer and the protective layer is formed by the CVD process or the like. A surface of the flow path forming substrate opposite to the wiring layer is wet-etched so that the release layer and the protective layer are removed. Moreover, the surface of the flow path forming substrate opposite to the wiring layer is wet-etched so that the wiring layer is removed and the flow path forming substrate is penetrated, thereby forming the reservoir.
At this time, liquid performing the wet etching enters into the reservoir forming plate from the penetrated portion, whereby the connection wiring formed on the surface of the reservoir forming plate opposite to the flow path forming substrate is damaged. To prevent such damage, JP-A-2006-088665 discloses a technique of sealing the connection wiring side of the reservoir portion by a film such as PPS (polyphenylene sulfide) or the like.
However, the etching solution for performing the wet etching may sometimes leak from the opening portion of the reservoir portion which has been sealed, damaging the connection wiring formed in the reservoir forming plate, thus leading to a break in the wiring or the like.